The most common and most likely answer to this crossword clue is the 11 letter word COMPARTMENT
I've seen this crossword clue in The Sunday Telegraph
C
O
M
P
A
R
T
M
E
N
T
More clues leading to the result COMPARTMENT
Buddy explains!

The straight part
We know that "section" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case section = compartment.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does COMPARTMENT mean?
COMPARTMENT noun- A room, or section, or chamber
- One of the parts into which an area is subdivided.
- Part of a protein that serves a specific function.
- A mound (often of grass) beneath the shield in a coat of arms on which the supporters stand.
- A region in the body, delimited by a biological membrane.
- To arrange in separate compartments.